White Oak Bark (Quercus alba) is the classic example of an astringent due to its high calcium and tannins content. For external use, boil or steam the bark and/or the leaves and apply them over the area needing treatment to relieve bruises, injuries, varicosities, swollen tissues and bleeding. It also helps strengthen capillaries. White oak has been used to treat diarrhea, dysentery and bleeding. In case of a loose tooth, it will help to strengthen the tissues and helps the tooth stay in place. White oak bark has been used to expel pinworms and for cleansing the entire gastrointestinal tract; it also helps remove kidney stones and gallstones. It stops bleeding in the stomach, liver, lungs and bowels. White oak bark has been used for excess mucus with common complaints such as sinus congestion and post-nasal drip.